UI基础 - 训练营：使用UISlider变换视图

使用 UISlider 变换视图

1 - 我们利用 UISlider 控制 RGB 的值从而达到视图颜色变更的目的。下面代码中 UISlider 改变视图颜色、UISwitch 隐藏视图、UIStepper 控制视图大小

// - ViewController

#import "RootViewController.h"
@interface RootViewController(){
    
    CGFloat  _red;
    CGFloat  _green;
    CGFloat  _blue;
    UIView * _aView;
}
@property (nonatomic, retain)UIView *redView;
@property (nonatomic, retain)UIView *greenView;

@end

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    NSArray *arrayTitle = [NSArray arrayWithObjects:@"红色视图",@"绿色视图", nil];
    UISegmentedControl *segment = [[UISegmentedControl alloc] initWithItems:arrayTitle];
    segment.frame = CGRectMake(60, 80, 200, 30);
    // _redView | _greenView 相互切换
    [segment addTarget:self action:@selector(trigger:) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:segment];
    
    
    // 红色视图
    self.redView = [[UIView alloc] initWithFrame:CGRectMake(30, 140, 115, 180)];
    _redView.backgroundColor = [UIColor redColor];
    [self.view addSubview:_redView];
    // 绿色视图
    self.greenView = [[UIView alloc] initWithFrame:CGRectMake(175, 140, 115, 180)];
    _greenView.backgroundColor = [UIColor greenColor];
    [self.view addSubview:_greenView];

    
    // 红色视图
    // 标题
    UILabel *redLabel = [[UILabel alloc] initWithFrame:CGRectMake(30, 350, 40, 30)];
    redLabel.text = @"R";
    redLabel.font = [UIFont boldSystemFontOfSize:20];
    redLabel.textColor = [UIColor redColor];
    [self.view addSubview:redLabel];
    // UISlider
    UISlider *redSlider = [[UISlider alloc] initWithFrame:CGRectMake(80, 350, 210, 30)];
    redSlider.tag = 100;
    // 滑动条颜色
    redSlider.minimumTrackTintColor = [UIColor redColor];
    redSlider.maximumTrackTintColor = [UIColor darkGrayColor];
    [self.view addSubview:redSlider];
    [redSlider addTarget:self action:@selector(changeColor:) forControlEvents:UIControlEventValueChanged];
    
    
    // 绿色视图
    UILabel *greenLabel = [[UILabel alloc] initWithFrame:CGRectMake(30, 390, 40, 30)];
    greenLabel.text = @"G";
    greenLabel.font = [UIFont boldSystemFontOfSize:20];
    greenLabel.textColor = [UIColor greenColor];
    [self.view addSubview:greenLabel];
    
    
    UISlider *greenSlider = [[UISlider alloc] initWithFrame:CGRectMake(80, 390, 210, 30)];
    greenSlider.tag = 101;
    greenSlider.minimumTrackTintColor = [UIColor greenColor];
    greenSlider.maximumTrackTintColor = [UIColor darkGrayColor];
    [self.view addSubview:greenSlider];
    [greenSlider addTarget:self action:@selector(changeColor:) forControlEvents:UIControlEventValueChanged];
    
    
    UILabel *blueLabel = [[UILabel alloc] initWithFrame:CGRectMake(30, 430, 40, 30)];
    blueLabel.text = @"B";
    blueLabel.font = [UIFont boldSystemFontOfSize:20];
    blueLabel.textColor = [UIColor blueColor];
    [self.view addSubview:blueLabel];

    
    UISlider *blueSlider = [[UISlider alloc] initWithFrame:CGRectMake(80, 430, 210, 30)];
    blueSlider.tag = 102;
    blueSlider.minimumTrackTintColor = [UIColor blueColor];
    blueSlider.maximumTrackTintColor = [UIColor darkGrayColor];
    [self.view addSubview:blueSlider];
    [blueSlider addTarget:self action:@selector(changeColor:) forControlEvents:UIControlEventValueChanged];

    
    UILabel *swiLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 500, 80, 30)];
    swiLabel.text = @"隐藏/显示";
    [self.view addSubview:swiLabel];

    
    // UISwitch 大小不能自定义，只能定义它的位置
    UISwitch *swit = [[UISwitch alloc] initWithFrame:CGRectMake(85, 500, 30, 50)];
    swit.on = YES;//初始为 ON 的一边
    [swit addTarget:self action:@selector(showOrHideView:) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:swit];
    

    UILabel *setLabel = [[UILabel alloc] initWithFrame:CGRectMake(140, 500, 80, 30)];
    setLabel.text = @"减小/增大";
    [self.view addSubview:setLabel];
    
    
    // stepper：减小/放大
    UIStepper *stepper = [[UIStepper alloc] initWithFrame:CGRectMake(220, 500, 60, 40)];
    stepper.tag = 105;
    [stepper addTarget:self action:@selector(changeSize:) forControlEvents:UIControlEventValueChanged];
    stepper.minimumValue =10;  // 最小高度
    stepper.maximumValue = 210;// 最大高度
    stepper.value = 0;     // 初始值
    stepper.stepValue = 10;// 递变量10
    [self.view addSubview:stepper];
}

-(void)trigger:(UISegmentedControl*)segment{
    
    switch (segment.selectedSegmentIndex) {
            
        case 0:{
            _aView = _redView;
            UIStepper *stepper1 = (UIStepper *)[self.view viewWithTag:105];
            stepper1.value = _aView.bounds.size.height;
            //NSLog(@"%f",stepper1.value);
            break;
        }
            
        case 1:{
            
            _aView = _greenView;
            UIStepper *stepper1 = (UIStepper *)[self.view viewWithTag:105];
            stepper1.value = _aView.bounds.size.height;
            // NSLog(@"%f",stepper1.value);
            break;
        }
        default:
            break;
    }
}

- (void)changeSize:(UIStepper *)stepper{

    if (stepper.value > _aView.bounds.size.height ) {
        
        _aView.bounds = CGRectMake(_aView.bounds.origin.x, _aView.bounds.origin.y, _aView.bounds.size.width, _aView.bounds.size.height + stepper.stepValue);
    }
    
    if (stepper.value < _aView.bounds.size.height) {
        
        _aView.bounds = CGRectMake(_aView.bounds.origin.x, _aView.frame.origin.y , _aView.bounds.size.width, _aView.bounds.size.height - stepper.stepValue);
    }
}

- (void)changeColor:(UISlider *)slider{
    if (slider.tag == 100) {
        _red = slider.value;
    }
    if (slider.tag == 101) {
        _green = slider.value;
    }
    if (slider.tag == 102) {
        _blue = slider.value;
    }
    // 颜色
    _aView.backgroundColor = [UIColor colorWithRed:_red green:_green blue:_blue alpha:1.0];
}

- (void)showOrHideView:(UISwitch *)swit{
    if (swit.on == YES) {
        _aView.hidden = NO;
    }
    if (swit.on == NO) {
        _aView.hidden = YES;
    }
}

@end

运行效果：初始化 | 选中绿色视图（修改）